1/*
2 *  linux/arch/m32r/kernel/signal.c
3 *
4 *  Copyright (c) 2003  Hitoshi Yamamoto
5 *
6 *  Taken from i386 version.
7 *  Copyright (C) 1991, 1992  Linus Torvalds
8 *
9 *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
10 *  2000-06-20  Pentium III FXSR, SSE support by Gareth Hughes
11 */
12
13#include <linux/sched.h>
14#include <linux/mm.h>
15#include <linux/smp.h>
16#include <linux/kernel.h>
17#include <linux/signal.h>
18#include <linux/errno.h>
19#include <linux/wait.h>
20#include <linux/unistd.h>
21#include <linux/stddef.h>
22#include <linux/personality.h>
23#include <linux/freezer.h>
24#include <asm/cacheflush.h>
25#include <asm/ucontext.h>
26#include <asm/uaccess.h>
27
28#define DEBUG_SIG 0
29
30#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
31
32int do_signal(struct pt_regs *, sigset_t *);
33
34asmlinkage int
35sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize,
36		  unsigned long r2, unsigned long r3, unsigned long r4,
37		  unsigned long r5, unsigned long r6, struct pt_regs *regs)
38{
39	sigset_t saveset, newset;
40
41	if (sigsetsize != sizeof(sigset_t))
42		return -EINVAL;
43
44	if (copy_from_user(&newset, unewset, sizeof(newset)))
45		return -EFAULT;
46	sigdelsetmask(&newset, ~_BLOCKABLE);
47
48	spin_lock_irq(&current->sighand->siglock);
49	saveset = current->blocked;
50	current->blocked = newset;
51	recalc_sigpending();
52	spin_unlock_irq(&current->sighand->siglock);
53
54	regs->r0 = -EINTR;
55	while (1) {
56		current->state = TASK_INTERRUPTIBLE;
57		schedule();
58		if (do_signal(regs, &saveset))
59			return regs->r0;
60	}
61}
62
63asmlinkage int
64sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
65		unsigned long r2, unsigned long r3, unsigned long r4,
66		unsigned long r5, unsigned long r6, struct pt_regs *regs)
67{
68	return do_sigaltstack(uss, uoss, regs->spu);
69}
70
71
72/*
73 * Do a signal return; undo the signal stack.
74 */
75
76struct rt_sigframe
77{
78	int sig;
79	struct siginfo __user *pinfo;
80	void __user *puc;
81	struct siginfo info;
82	struct ucontext uc;
83//	struct _fpstate fpstate;
84};
85
86static int
87restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
88		   int *r0_p)
89{
90	unsigned int err = 0;
91
92	/* Always make any pending restarted system calls return -EINTR */
93	current_thread_info()->restart_block.fn = do_no_restart_syscall;
94
95#define COPY(x)		err |= __get_user(regs->x, &sc->sc_##x)
96	COPY(r4);
97	COPY(r5);
98	COPY(r6);
99	COPY(pt_regs);
100	/* COPY(r0); Skip r0 */
101	COPY(r1);
102	COPY(r2);
103	COPY(r3);
104	COPY(r7);
105	COPY(r8);
106	COPY(r9);
107	COPY(r10);
108	COPY(r11);
109	COPY(r12);
110	COPY(acc0h);
111	COPY(acc0l);
112	COPY(acc1h);		/* ISA_DSP_LEVEL2 only */
113	COPY(acc1l);		/* ISA_DSP_LEVEL2 only */
114	COPY(psw);
115	COPY(bpc);
116	COPY(bbpsw);
117	COPY(bbpc);
118	COPY(spu);
119	COPY(fp);
120	COPY(lr);
121	COPY(spi);
122#undef COPY
123
124	regs->syscall_nr = -1;	/* disable syscall checks */
125	err |= __get_user(*r0_p, &sc->sc_r0);
126
127	return err;
128}
129
130asmlinkage int
131sys_rt_sigreturn(unsigned long r0, unsigned long r1,
132		 unsigned long r2, unsigned long r3, unsigned long r4,
133		 unsigned long r5, unsigned long r6, struct pt_regs *regs)
134{
135	struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->spu;
136	sigset_t set;
137	int result;
138
139	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
140		goto badframe;
141	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
142		goto badframe;
143
144	sigdelsetmask(&set, ~_BLOCKABLE);
145	spin_lock_irq(&current->sighand->siglock);
146	current->blocked = set;
147	recalc_sigpending();
148	spin_unlock_irq(&current->sighand->siglock);
149
150	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &result))
151		goto badframe;
152
153	if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->spu) == -EFAULT)
154		goto badframe;
155
156	return result;
157
158badframe:
159	force_sig(SIGSEGV, current);
160	return 0;
161}
162
163/*
164 * Set up a signal frame.
165 */
166
167static int
168setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
169	         unsigned long mask)
170{
171	int err = 0;
172
173#define COPY(x)	err |= __put_user(regs->x, &sc->sc_##x)
174	COPY(r4);
175	COPY(r5);
176	COPY(r6);
177	COPY(pt_regs);
178	COPY(r0);
179	COPY(r1);
180	COPY(r2);
181	COPY(r3);
182	COPY(r7);
183	COPY(r8);
184	COPY(r9);
185	COPY(r10);
186	COPY(r11);
187	COPY(r12);
188	COPY(acc0h);
189	COPY(acc0l);
190	COPY(acc1h);		/* ISA_DSP_LEVEL2 only */
191	COPY(acc1l);		/* ISA_DSP_LEVEL2 only */
192	COPY(psw);
193	COPY(bpc);
194	COPY(bbpsw);
195	COPY(bbpc);
196	COPY(spu);
197	COPY(fp);
198	COPY(lr);
199	COPY(spi);
200#undef COPY
201
202	err |= __put_user(mask, &sc->oldmask);
203
204	return err;
205}
206
207/*
208 * Determine which stack to use..
209 */
210static inline void __user *
211get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
212{
213	/* This is the X/Open sanctioned signal stack switching.  */
214	if (ka->sa.sa_flags & SA_ONSTACK) {
215		if (sas_ss_flags(sp) == 0)
216			sp = current->sas_ss_sp + current->sas_ss_size;
217	}
218
219	return (void __user *)((sp - frame_size) & -8ul);
220}
221
222static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
223			   sigset_t *set, struct pt_regs *regs)
224{
225	struct rt_sigframe __user *frame;
226	int err = 0;
227	int signal;
228
229	frame = get_sigframe(ka, regs->spu, sizeof(*frame));
230
231	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
232		goto give_sigsegv;
233
234	signal = current_thread_info()->exec_domain
235		&& current_thread_info()->exec_domain->signal_invmap
236		&& sig < 32
237		? current_thread_info()->exec_domain->signal_invmap[sig]
238		: sig;
239
240	err |= __put_user(signal, &frame->sig);
241	if (err)
242		goto give_sigsegv;
243
244	err |= __put_user(&frame->info, &frame->pinfo);
245	err |= __put_user(&frame->uc, &frame->puc);
246	err |= copy_siginfo_to_user(&frame->info, info);
247	if (err)
248		goto give_sigsegv;
249
250	/* Create the ucontext.  */
251	err |= __put_user(0, &frame->uc.uc_flags);
252	err |= __put_user(0, &frame->uc.uc_link);
253	err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
254	err |= __put_user(sas_ss_flags(regs->spu),
255			  &frame->uc.uc_stack.ss_flags);
256	err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
257	err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
258	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
259	if (err)
260		goto give_sigsegv;
261
262	/* Set up to return from userspace.  */
263	regs->lr = (unsigned long)ka->sa.sa_restorer;
264
265	/* Set up registers for signal handler */
266	regs->spu = (unsigned long)frame;
267	regs->r0 = signal;	/* Arg for signal handler */
268	regs->r1 = (unsigned long)&frame->info;
269	regs->r2 = (unsigned long)&frame->uc;
270	regs->bpc = (unsigned long)ka->sa.sa_handler;
271
272	set_fs(USER_DS);
273
274#if DEBUG_SIG
275	printk("SIG deliver (%s:%d): sp=%p pc=%p\n",
276		current->comm, current->pid, frame, regs->pc);
277#endif
278
279	return;
280
281give_sigsegv:
282	force_sigsegv(sig, current);
283}
284
285/*
286 * OK, we're invoking a handler
287 */
288
289static void
290handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
291	      sigset_t *oldset, struct pt_regs *regs)
292{
293	unsigned short inst;
294
295	/* Are we from a system call? */
296	if (regs->syscall_nr >= 0) {
297		/* If so, check system call restarting.. */
298		switch (regs->r0) {
299		        case -ERESTART_RESTARTBLOCK:
300			case -ERESTARTNOHAND:
301				regs->r0 = -EINTR;
302				break;
303
304			case -ERESTARTSYS:
305				if (!(ka->sa.sa_flags & SA_RESTART)) {
306					regs->r0 = -EINTR;
307					break;
308				}
309			/* fallthrough */
310			case -ERESTARTNOINTR:
311				regs->r0 = regs->orig_r0;
312				inst = *(unsigned short *)(regs->bpc - 2);
313				if ((inst & 0xfff0) == 0x10f0)	/* trap ? */
314					regs->bpc -= 2;
315				else
316					regs->bpc -= 4;
317		}
318	}
319
320	/* Set up the stack frame */
321	setup_rt_frame(sig, ka, info, oldset, regs);
322
323	spin_lock_irq(&current->sighand->siglock);
324	sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
325	if (!(ka->sa.sa_flags & SA_NODEFER))
326		sigaddset(&current->blocked,sig);
327	recalc_sigpending();
328	spin_unlock_irq(&current->sighand->siglock);
329}
330
331/*
332 * Note that 'init' is a special process: it doesn't get signals it doesn't
333 * want to handle. Thus you cannot kill init even with a SIGKILL even by
334 * mistake.
335 */
336int do_signal(struct pt_regs *regs, sigset_t *oldset)
337{
338	siginfo_t info;
339	int signr;
340	struct k_sigaction ka;
341	unsigned short inst;
342
343	/*
344	 * We want the common case to go fast, which
345	 * is why we may in certain cases get here from
346	 * kernel mode. Just return without doing anything
347	 * if so.
348	 */
349	if (!user_mode(regs))
350		return 1;
351
352	if (try_to_freeze())
353		goto no_signal;
354
355	if (!oldset)
356		oldset = &current->blocked;
357
358	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
359	if (signr > 0) {
360		/* Reenable any watchpoints before delivering the
361		 * signal to user space. The processor register will
362		 * have been cleared if the watchpoint triggered
363		 * inside the kernel.
364		 */
365
366		/* Whee!  Actually deliver the signal.  */
367		handle_signal(signr, &ka, &info, oldset, regs);
368		return 1;
369	}
370
371 no_signal:
372	/* Did we come from a system call? */
373	if (regs->syscall_nr >= 0) {
374		/* Restart the system call - no handlers present */
375		if (regs->r0 == -ERESTARTNOHAND ||
376		    regs->r0 == -ERESTARTSYS ||
377		    regs->r0 == -ERESTARTNOINTR) {
378			regs->r0 = regs->orig_r0;
379			inst = *(unsigned short *)(regs->bpc - 2);
380			if ((inst & 0xfff0) == 0x10f0)	/* trap ? */
381				regs->bpc -= 2;
382			else
383				regs->bpc -= 4;
384		}
385		if (regs->r0 == -ERESTART_RESTARTBLOCK){
386			regs->r0 = regs->orig_r0;
387			regs->r7 = __NR_restart_syscall;
388			inst = *(unsigned short *)(regs->bpc - 2);
389			if ((inst & 0xfff0) == 0x10f0)	/* trap ? */
390				regs->bpc -= 2;
391			else
392				regs->bpc -= 4;
393		}
394	}
395	return 0;
396}
397
398/*
399 * notification of userspace execution resumption
400 * - triggered by current->work.notify_resume
401 */
402void do_notify_resume(struct pt_regs *regs, sigset_t *oldset,
403		      __u32 thread_info_flags)
404{
405	/* Pending single-step? */
406	if (thread_info_flags & _TIF_SINGLESTEP)
407		clear_thread_flag(TIF_SINGLESTEP);
408
409	/* deal with pending signal delivery */
410	if (thread_info_flags & _TIF_SIGPENDING)
411		do_signal(regs,oldset);
412
413	clear_thread_flag(TIF_IRET);
414}
415